1. Field of the Invention
The present invention relates to a high-frequency module and a communication device including such a high-frequency module. In particular, the present invention relates to a high-frequency module including a plurality of demultiplexers, and a communication device including such a high-frequency module.
2. Description of the Related Art
In recent years, in communication services involving cellular phones, for example, dealing with an increase in the number of subscribers, the realization of global roaming enabling use worldwide, the improvement of communication quality, the capacity enlargement of various kinds of contents have been promoted. So as to deal with such communication services, it is necessary to make communication devices such as mobile phones responsive to the realization of multiple bands or a plurality of communication systems.
Therefore, for example, in a communication device compatible with a plurality of bands in a UMTS (Universal Mobile Telecommunications System), a plurality of duplexers corresponding to individual bands and individual communication systems to be used are mounted in an RF (Radio Frequency) circuit. As an example of such a communication device, for example, a communication device described in Japanese National Publication of International Patent Application No. 2003-517239 may be cited and includes a high-frequency module including two duplexers. In addition, the duplexer is a demultiplexer including a transmission filter, a reception filter, and a matching circuit.
However, in the high-frequency module described in Japanese National Publication of International Patent Application No. 2003-517239, an Inter-Modulation Distortion (IMD) occurs in the duplexer, and in some cases, a problem that the receiving sensitivity of the communication device is deteriorated occurs.